I accidentally slept on my phone and when I checked it the next day, it was restarting on its own and this would last for a minute. Before it completely shut down, the power button wouldn't work. Now that it's completely off I tried charging it and waited for 15 minutes but nothing happened. I would press the power button for 10 seconds but it only buzzed for a second, I also tried pressing down the volume buttons and power buttons together for 1 minute and nothing still worked. Please help, I've been trying to fix it for 2 days. By the way my phone is a Huawei Mate 7 and I can't take out the battery